Marzena H. Szymanska

Department of Physics and Astronomy
University College London

Driven-dissipative quantum fluids of light, experimentally realised in for example semiconductor microcavities, circuit or cavity QED systems, provide a unique testbed to explore new non-equilibrium quantum phenomena. I will review recent progress in this field. In particular, we show that polariton quantum fluid can exhibit a non-equilibrium order, where superfluidity is accompanied by stretched exponential decay of correlations ^[1]. This celebrated Kardar-Parisi-Zhang (KPZ) phase has not been achieved before in any system in 2D, and even 1D realisations have not been conclusive. I will then discuss how these systems can undergo other unconventional phase transitions and orders ^[2], and display flow properties connected but distinct from conventional superfluidity. Finally, when placed in strained honeycomb lattice potentials, polariton fluids can condense into a rotating state, the lowest Landau level, forming a vortex array and spontaneously breaking time reversal symmetry ^[3]. Describing strong quantum correlations in open systems with drive and dissipation, especially in two dimensions, is a numerical challenge. I will briefly present our attempts at developing suitable methods, based on stochastic and tensor network approaches ^[4].

Zoom registration link:
https://zoom.us/meeting/register/tJ0tdu2tpz0oH9Tkny22wffqEBd_F7cBVTOJ